The invention is involved with making improved polymers and compositions employing these polyers.
The herein disclosed invention is concerned with making improved polymer compositions for use as scaffolds for incorporating cells to be used for tissue repair. The invention is also concerned with making improved polymer compositions for use as agents to prevent tissue adhesion after surgery and as wound healing agents. The polymer compositions can also be used as aids to cell culture.
An object of this invention is to produce polymer constructs upon which cells can be cultured.
A main object of this invention is to prepare polymer scaffolds on which cells can be grown and thereafter used as tissue replacements.
A further object of this invention is to produce devices such as films, sheets or powders for preventing tissue adhesion. Examples of surgery requiring tissue adhesion prevention are gynecological and abdominal surgery.
An object of this invention is to produce polymer compositions useful as wound healing agents.
These and other objects of the present invention will become apparent from a reading of the following specification taken in conjunction with the enclosed drawings.
The herein disclosed invention encompasses an overall process starting with a method of obtaining cells such as chondrocytes, preparing the chondrocytes for transplantation and then actually transplanting them. The invention can be conceptualized as being divided into various phases. These phases can generally be identified as follows:
Phase I
Phase I of this invention involves an elegant and efficient method of obtaining cartilage from which there is to be obtained chondrocytes. The herein disclosed invention covers not only the obtaining of cartilage from conventional sources, but also cartilage from the nose.
Phase II
This phase involves obtaining a sample of cartilage as the source of chondrocytes; then deriving chondrocytes from said cartilage.
The obtaining of cells and cell sources such as stromal cells and stem cells are contemplated as being part of this phase of the invention.
Phase III
This phase involves culturing cells and particularly chondrocytes, so as to obtain optimum amounts and optimum quality of cells by monitoring culture conditions. The conditions to be monitored would involve for example:
1) The spin rate and conditions of spin.
2) Type of microcarrier or microbeadlet producing optimum results.
3) The culture media producing optimum growth of good quality chondrocytes or cells.
4) The temperature during culture.
5) The pressure employed during culture.
6) Amount of oxygen employed during culture.
7) Amount of CO2 employed during culture.
8) Degree of Integrin expression.
9) The phenotype of chondrocytes.
10) Optimum concentration of cells in culture, e.g., removing cells to retain an optimum concentration of cells during culture.
11) Replenish culture media.
12) Ascertain that cells are producing proper metabolic by-products.
13) Electro-magnetic stimulation.
14) Addition of growth factors to the culture media, e.g. TGF.
15) Varying culture conditions for chondrocytes between spin-culture, surface culture and stretch culture.
16) Pressure and mechanical strain.
An important aspect of the cell culture of this invention comprises optimizing the production of cells, e.g chondrocytes by a servo controlled mechanism which has been perfected to control culture conditions so as to produce optimum quantities and qualities of cells.
It is to be understood that these culture techniques are not only applicable to chondrocytes, but also to other cells such as osteoblasts and stem cells.
Phase IV
This phase involves preparing scaffold material and microcarriers upon which cells are to be grown and then transplanted as a prosthesis; particularly chondrocytes on a scaffold are to be used for cartilage repair or replacement. The scaffold material will take the shape of the body part to be replaced, and further the scaffold material can, for example, be in the form of a mesh, sponge or like porous body. Various polymers such as polysaccharide polymers are envisioned as being operative in this invention.
Phase V
This phase involves preparing a cell-implanted scaffold. Once the scaffold per se is obtained in its proper shape, it can be cultured along with chondrocytes to prepare a prosthesis for cartilage repair. Special culture techniques, such as the application of pressure, are visualized as being necessary for proper manufacture of the cell implanted scaffold.
Phase VI
This phase embraces surgical techniques for implanting the scaffold for cartilage repair or repair of other body defects such as skin, etc. Not only are humans to be surgically treated by the methods of this invention, but also animals such as horses.
Phase VII
In carrying out the procedures of this invention, FDA guidelines will be followed. Tests and methods for improving and complying with regulatory guidelines are to be advanced.
Phase VIII
This invention also embraces a phase in which polymer constructs are prepared and used as tissue-adhesion prevention agents, polymer constructs on which cells are grown and constructs used for wound-healing and tissue repair.
The herein disclosed invention embraces use mainly culturing cells, Phase III; preparing scaffold material, Phase IV; preparing scaffold, Phase V and polymer constructs used for tissue adhesion prevention and cell culture, Phase VIII.
AG=Arabinoglactan
PLA=poly (lactide)
PLGA=poly (lactidexe2x80x94glycolide)